As the commercial demand for semiconductor devices (e.g., memory chips and microprocessors) increases, testing of these devices has become critical for device manufacturers. By testing semiconductor devices prior to shipping to their customers, defective or under-performing devices may be detected and removed. To perform such tests, semiconductor device testers such as automatic test equipment (ATE) may be used to characterize and validate the performance of manufactured semiconductor devices.
For some types of tests, the ATE may send two types of signals to a device-under-test (DUT). Direct current (DC) signals are sent to the DUT for measuring device characteristics such as input and output impedance, leakage current, and DUT performance. To produce and send these DC signals, the ATE includes a parametric measurement unit (PMU). The ATE also generates and sends alternating current (AC) signals to the DUT, which for some test scenarios simulate digital signals. These simulated digital signals, for example, may be input into a memory chip under test. After storing the digital values represented by the digital signals, the values are retrieved (at a later time) to determine if the DUT has properly stored the values. To generate and send the AC test signals, the ATE includes additional circuitry known as Pin Electronics (PE) circuitry that typically operates at higher speeds compared to the PMU circuitry. Due to the slower PMU circuitry, PMU tests typically use more test time than PE tests.